Cutterhead for hair clippers



Sept 30, 1952 M. BROWN ErAL 2,611,955

' CUTTERHEAD FOR HAIR CLIPPERS Filed Jan. '31, 1949 9W E1215 M. Brawn .Ernes ifrss \C %g I cousin Application January 31, 1949, SerialNo. 73,831 g 4Claims. (01.30-223) PATENT CUTTERHEAD FOB, HAIn'cLIrrEns Ellis M. Brown and Ernest Harry Forss, Racine, Wis.,. assignors to John Oster Manufacturing Company, Racine, Wis.', a corporation of Wis- This invention relates to hair clippers and refers particularlyto the cutter head thereof.

Practically all hair clippers now in use, whether hand operated or power driven, employ a cutter head consisting of complementary upper and lower blades, the front edges of which are toothed to effect a shearing action as the movable blade is shifted laterally across the stationary blade.

Obviously the blades must be held together under tension to'enable proper shearing action, and in the past many different ways have been employed to obtain this necessary tension. Where the tensioning means employs adjusting screws or the like the user of the clipper often disturbs the proper setting of the tension with the result that the clipper does not perform satisfactorily.

It is, therefore, an object of the present invention to provide a cutter head for hair clippers wherein the tensioning means is so constructed as to afford fairly reliable assurance against meddling with the factory set tension.

In most cutter heads heretofore in use the blades have a crosshead-like interengagement constraining the movable blade to linear reciprocation, and the tensioning means merely holds the movable blade on its tracks so to speak.

With a view toward eliminating the obvious expense of machining the tracks and guideways forming the crosshead, it is another object of this invention to provide a cutter head wherein the tensioning means not only holds the blades together under proper tension but'also servesas the sole support for the movable blade and in itself holds the same in proper relationship to the stationary blade.

The manner of driving the movable blade in cutter heads heretofore in use generally consisted of a socket formed in the blade and a rocking lever having an end portion thereof receivedin the socket. This construction becomes noisy in use due to the increasing clearance between the parts resulting from the inevitable wear. To overcome this disadvantage the present invention has as another of its objects to providean improved manner of drivingly connecting the movable blade with the power driven actuator.

In this connection it is a further object of this invention to so construct the tensioning means that it performs this additional function of transmitting motion from the actuator to the blade.

Finally it is the purpose of this invention to reducethe cost of manufacturing the cutter head of hair clippers.

With the above and other objects in view which will appear. as the description proceeds, this inverition resides in the-novel constructio' bination and arrangement of parts substantially? as hereinafter described, and morepar-ticularly defined by the appended claims,'-it being' i-inder-' stood that such changes in the preciseembodif ment of the hereindisclosed invention may 10 made as come within the scope of the claims.

The accompanying drawing illustrates-bum complete example of the physi'ca1 embodiment o f the invention constructed in accordance" with the best mode so far devised for the practica application of the principles thereof, nd which:

Figure l is aside view of an electric h'air clip per having the cutter head of this invention appliedthereto, parts thereof being broken way and in section; f f F i Figure 2 is a perspective view of the cutter head and the front end portion of the clipper-j} and w I Figure 3 is aside view of the combination blade tensioning and driving unit. f Referring now particularly to the acc mpanyg ing drawing in which like numerals' desi'gnatelike parts throughout: the" several views, the humeralli designates generally an electric hair clipper which maybe of the type forming the sum; ject matter of the copending"application?serial No. 73.832, filed January 31, 1949.

shown) housed within a gearcase 8. 4 1 L The front. endof the housing 6 slants up-' wardly and is partially closed by a wall 9 to which a cutter head indicated generally byih'e; n'u meral I!) is removably securedby screws'l i'-.- *T'h'e' cutter head I0 comprises a stationary lowfr jblade l2 and a movable upper blade l 3 arrangedin superimposed relation with the upper movable blade adapted to move freely across {the top of the stationary blade.

As is customary, the complementaryb ds have cutting teeth 14 along the front'edg he of which effect the desired shearingaction, dur

1 l5 and H5 in sliding superimposition so that-the.

' movable, blade is free .tomovein all directionsg' ing sidewise reciprocationjof the .movableblade As distinguished from past constructions there.

is no crosshead constraining the movable blade,

to linear motion. Instead the aajac n rae spr" with respect to the stationary blade. The elimination of the crosshead or interengaging trackways heretofore used to constrain the movable blade to linear reciprocation obviously effects a reduction in the cost of manufacture since all finishing of the meeting surfaces involves merely a surface; grindingjoperation which alsov sharpens.

the blades The blades are held together under tension by means of a novel spring yoke I1, anchored to the .stationary blade I2 and overlyineand bearing down on the movable blade 13. This yoke is formed of spring steel and. is substantially U.- shaped with its closed end [8 flat and secured to an upstanding tongue IS on arrattachingsbracket.

20, the bracket 20 being fastened to the back of the stationary blade by screws 2L.

The free endsof the arms 22 of the'yoke are detachably secured to the movable blade by pins.

23 fastened to laterally extending ears 24 on the arms: Hyena received in holes, 25 in the movable rected; downwardly to bear down on the movable blade with :a spring tension depending upon the angle towhich the tongue (9 is bent.

-f The bracket with its integral tongue 19 is made oi' semi-hard steel so that it normally resists deformation but can be bent at the factory to; obtain proper spring tension, and as will be readilyapparent; sincethis manner of adjusting theblade tension involves noscrews or the like it affords fairly reliable assurance against the user ofrthe' clippermeddling with the spring tension and therebyi-nterfering with properfunctioning ofrthe cutter. head, Also, since the. cutter. head is an assembly complete initself and independent from. the clipper, replacement and interchangeability of cutter heads, is facilitated.

In the application of. the; cutter head to. the

clippen-the inner anchored end of the spring yokeisreceivedtin a cutout 2B in thefront wall 9.. ofxthe-i clipper housing, and. the eccentric 1 snugly enters thespace between the outer ends of; thespring arms. To provide increased bearing surfaces betweenthe arms andv the eccentric:-the, width of the arms is increased by rear-- wardnextensions 21 on the free ends. of the arms. Thus: as; the eccentric, revolves the arms of the spr n yoke are flexed back and forth to swing themovablecutter blade l3 in a wide arc. Hence, the two spring arms-of. the yoke are pivoted. at. their outer. ends. to the movable cutter. blade, the mounting of the blade forms substantially a parallelogram so 'that'the cutting edges of the. blades are always parallel, and as the are through which the. movable blade is swung. is. verynearly fiat, for all practical purposes the motion of the blade l3 may lee-characterized as reciprocation.

From the foregoing description taken in connection with the accompanying drawing, it will bereadily apparent. to those skilled in the art thatfthis; invention provides a cutter head for haifclippers which. possesses many advantages over those heretofore available, particularly as to the cost of manufacture and freedom from meddling adjustment of. blade tension by unskilled persons.

What-we claim as our invention is:

l. cutter head for hair clippers, comprising: astationary blade having a back" edge and a toothed front edge; a movable blade superimposed upon the stationary blade and having cutter teeth on its front edge coacting with the teeth of the stationary blade; a U-shaped spring yoke having substantially parallel blade-like arms flatwise opposing one another and relatively close together, said blade-like arms having a length slightly less than the distance between' the front and back edges of the stationary blade, and the free end portions of the blade-like arms providing spaced opposed driving abutments to receive a rotatable driving eccentric therebetween; flanges on the free ends of the blade-like arms extending from the. outer sides of the arms adjacent to one edge. thereof and lying in a common plane-normal to the fiatwise planes of the blade-like armsga connection between the spring yoke. and the stationary blade mounting the yoke on the cutter head with the bight of the U spaced from but directly over and substantially aligned with the back edge of the stationary blade and the arms of the spring yoke projecting towardtl'iecutting edge of the head, and with the. flanges on the armspressed. fiatwise. down upon the movable. blade to hold the blades together under tensionsaid connection including resilient means. on. the bight of the U-shaped spring yoke projecting toward the free ends of the blade-like arms in spaced relation to the edges having the flanges extending therefrom and secured to the stationary blade; and means drivingly connecting theflanges on the free ends of the blade-like arms with the movable blade so that rotary motion of an ecentric. engaged. between said driving abutments may be yieldably translated into reciprocatory movement of the movable blade through the resilient blade-like arms of the spring yoke;

2.- The cutter head set forth in claim 1. furthercharacterized by the f'actthat the resilient means mounting the U-shaped spring yoke on. the stationary blade comprises a bracket having a base flatwisesecured to the stationary blade and an upstanding tongue attached to the bight of the U, said base and upstanding tongue'being. disposed at a slightly acute angle to one another posed upon the stationary blade and. having cutter teeth on its front edge coasting with the teeth of the lower blade; a U-shaped spring yoke having substantially parallel blade-like arms fiat-wise opposing one another and relatively close together, said arms having a length slightly less than the distance between the front and back edges of the stationary lower blade; flanges on the free ends of the blade-like arms extend..- ing from the outer sides of the arms adjacent to one side thereof and lying in a common plane normal to the planes of the arms; extensions on the edges of the blade-like arms opposite the fiangesand adjacent to the free ends of the arms and coplanar therewith, said extensions cooperating with the free end portions of the arms to provide spaced driving abutments to. receive a rotatable driving" eccentric therebetween and having thrust receiving surfaces of substantial area engageable. by the eccentric; resilient mounting means connected between thev bight.

of the U-shaped spring; yoke and the stationary blade, to: mount. the. yoke thereon with the bight of the U directly over and substantially aligned with the rear edge of the stationary blade and the blade-like arms of the spring yoke projecting toward the cutting edge of the head, and with the flanges on the arms pressed flatwise down upon the movable blade by the resilient mounting means to hold the blades together under tension; and means drivingly connecting the flanges on the free ends of the arms with the movable blade so that rotary motion of an eccentric engaged between said driving abutments may be yieldably translated into reciprocatory movement of the movable blade through the resilient blade-like arms of the spring yoke.

4. A cutter head for hair clippers including a stationary blade having a back edge and a toothed front edge, and a movable blade superimposed upon the upper side of the stationary blade with its back edge intermediate the front and back edges of the stationary blade and having cutter teeth on its front edge coasting with the teeth of the stationary blade: characterized by the provision of a bracket comprising a base portion flatwise secured to the upper side of the stationary blade, and an upstanding tongue resiliently joined to said base portion to be capable of flexure toward and from said base portion, said tongue being substantially in line with and extending upwardly with respect to the back edge of the stationary blade, and said base portion lying wholly between the back edges of the stationary and movable blades; and further characterized by the provision of a U-shaped spring yoke fixed to said tongue with its bight flatwise engaged with the tongue, said yoke having forwardly extending substantially parallel bladelike arms flatwise opposing one another and relatively close together, said arms being disposed edgewise to the upper side of the stationary blade and having a length slightly less than the distance between the front and back edges thereof, and said arms having flanges on their forward ends drivingly connected with the movable blade, said flanges extending from the outer sides of the arms adjacent to the lower edges thereof and yieldingly pressed flatwise down upon the movable blade by the tongue to hold the blades together under tension; and extensions on the upper edges of the arms coplanar with the blades and cooperating with the front end portions thereof to provide spaced driving abutments to receive a rotatable driving eccentric therebetween and having thrust receiving surfaces of substantial area engageable by the eccentric.

ELLIS M. BROWN. ERNEST HARRY FORSS.

REFERENCES CITED The following references are of record in the 

